ACTA ENDOCRINOLOGICA (BUC)

hormone (ACTH) mediated multisystemic state of adrenal hypercortisolism. An ACTH secreting benign pituitary tumor (adenoma) is the most common cause in the majority of patients with CD. Case report. This article describes a case of a 56-year-old woman presenting with clinical manifestations of hypercortisolism, with high plasma cortisol and ACTH levels that was suppressed with high-dose dexamethasone administration, suggestive of CD. Pituitary magnetic resonance imaging (MRI) of the sellar region was inconclusive. During the single photon emission computed tomography (SPECT) examination, an increased accumulation of technetium - 99m - hexakis - 2 - methoxy - isobutyl-isonitrile (99mTc-MIBI) in the pituitary gland area was noticed. Finally, response to corticotropinreleasing hormone (CRH) and ghrelin stimulatory testing, differentiated CD from ectopic ACTH and primary adrenocortical hypersecretion. Conclusion. We highlight the potential of 99mTc- MIBI SPECT as sensitive and specific method of pituitary gland adenoma detection in patients with Cushing’s disease, when MRI fails to directly detect an adenoma and stimulatory tests with CRH and ghrelin are not in routine diagnostics.

Context. The variety of tumor-seeking radiopharmaceuticals, which are currently in clinical use, may have a potential role as imaging agents for adrenal gland tumors, due to physiological characteristics of this organ. Objective. The purpose of this study was to evaluate the diagnostic potential of 99mTc-HYNIC-TOC, 99mTc(V)- DMSA, and 99mTc-MIBI in the assessment of adrenal tumors, by correlating with imaging findings and histopathologic results. Design. The research is designed as a crosssectional prospective study. Patients and method. The study included 50 patients with adrenal tumors (19 hormone-secreting and 31 nonfunctioning) and 23 controls without adrenal involvement. In all patients, single-photon emission computed tomography (SPECT) was performed, using qualitative and semiquantitative analysis. The tumor to nontumor tracer uptake was conducted by using a region-ofinterest technique. Adrenal to background (A/B) ratio was calculated in all cases. Results. 99mTc-HYNIC-TOC scintigraphy showed a high statistical significance between A/B ratios, while other two tracers resulted in a lower sensitivity, specificity and accuracy. Futhermore, 99mTc-HYNIC-TOC could have a high diagnostic yield to detect adrenal tumors (the receiveroperating- characteristic curve analysis, A/B ratio cut-off value of 8.40). Conclusion. A semiquantitative SPECT analysis showed that 99mTc-HYNIC-TOC is a highly sensitive tumorseeking agent for the accurate localization of adrenal tumors.

Objective. After total thyroidectomy, radioiodine (131I) treatment is a usual treatment in patients with differentiated thyroid cancer (DTC). Since most of ingested 131I is excreted by the kidneys, one of the procedures for enhancement of 131I excretion from the body is the use of diuretics. The aim of study was to investigate the effect of hydrochlorothiazide (HCTZ) administration on the excretion of 131I in the urine in patients with DTC treated with 131I. Design. Study included 90 patients with DTC, normal renal function and low 131I uptake in the thyroid gland region. Patients were divided into two groups: the group taking HCTZ and the control group. All patients underwent whole-body measurements of the radioactivity of 131I in the urine and in blood samples. Results. Blood radioactivity was significantly higher in the HCTZ group as compared to the control group (16380.89 vs. 11731.61cpm/mL/GBq; P=0.007). The residual radioactivity in the body and the exposed dose were higher in patients taking HCTZ (71.61 vs. 60.70MBq/ GBq and 7.05% vs. 6.14%) but this difference was not significant. During the first 36h from 131I administration the patients taking HCTZ excreted a higher percentage of the 131I than the controls (65.45±12.12% vs. 62.21±11.25%, P=0.032). During the second part of the hospitalization (36- 72h) the urinary excretion as reversed, so after 72h patients taking HCT excreted less 131I than controls, however, this difference was not significant (P=0.084; 76.54±10.16% vs. 83.81±13.46%). Conclusions. HCTZ given as additional treatment decreases urinary excretion of 131I as and should not be administered in patients under 131I treatment for DTC.